Whether going to tape or computer, the recording process is basically the same as it's been for decades, but those new to the experience may become a little lost by a lack of understanding of the process and the plethora of hardware and software choices available today.

A Brief Overview of Recording

Sound recording consists of capturing some kind of time-based signal, either from the analog or digital domain, and committing it to some kind of medium, either analog or digital, from which the signal can be played back.

One example is a person dictating into a handheld tape recorder. Though this example is simple, it does contain the basic parts of recording a live signal: the source (voice), the mechanism which translates sound waves into electrical signals (the microphone), and the recording mechanism (magnetic tape).

Playback goes in reverse: magnetic waves are converted to electrical, which are converted to sound waves (the speaker).

Recording to a computer isn't much different. though the source may be something other than moving soundwaves, the information must end up as a digital stream of 1's and 0's to be written to a hard drive (the recording mechanism).

Line in through the audio-in port

Macs with analog audio-in ports feature a cheap analog/digital converter tied to the audio-in port. This means that a line can be fed from, say, an outboard mixer and the computer will be able to record it, though with not much quality.

Note that line level is not the same as Hi-Z, which is a high impedance signal from, say, an electric guitar.

Mic in through the audio-in port

Mic-level signals are significantly lower than line-level signals. The device which increases a mic-level signal to line-level is called a microphone preamplifier, (also known as mic pre or pre).

Although the Mac audio-in port does have a built-in microphone preamplifier, it is accessible only through an Apple proprietary connector called PlainTalk. It seems this connector is longer than a standard 1/8" plug and can't access the microphone preamplifier's phantom power. Therefore, plugging in an OTS condenser microphone, with an XLR to 1/8" adapter, won't work.

USB and FireWire

Once we get to these ports, we're talking about connecting some kind of computer/audio interface. Sweetwater carries a number of such interfaces, which can be accessed here.

These computer interfaces typically offer analog ins, such as line level in, Hi-Z in, and microphone in. Any microphone interface will have a microphone preamplifier behind it, and probably phantom power, to power microphones which need external power, such as condenser microphones.

These interfaces will also have converters in them, at least analog/digital and usually digital/analog, for monitoring purposes. A major differentiator among models is the number of channels. There are many models with 2, 4, and 8 channels.

Other differentiating factors are quality, bundled software, brand and other features, such as headphone outputs, the ability to rackmount, and low-latency monitoring.

Advantages of such boxes include a higher quality preamplifier and converter than what's built into the Mac, increased channels, one-stop shopping and availability of features not offered on the Mac.

Disadvantages include, in general, a quality reflecting its price and a limited ability to upgrade components singly.

PCI card

These are similar in concept to the USB and FireWire boxes, though they obviously connect differently, tend to cost more and have higher quality. Some are not all-in-boxes, but rather simply converters, requiring a separate purchase of preamplifiers and other hardware.

Conclusion

As should now be obvious, there are a variety of methods to getting audio into the Mac. Each user must determine for themselves which method is most appropriate for their situation. Obviously, if one wants to multi-track an entire drumset, the audio-in port will not suffice.

Budget constraint is an obvious determiner, however you basically get what you pay for.

Regardless of which method is used, the audio is now in the Mac, digitized, and ready to be recorded to hard disk.

Whether you're using a PlainTalk microphone, or an sm57 and a presonus mic pre and an m-audio converter, all those components exist. This is important to understand, as it gets confusing when one plugs in a USB microphone (Samson makes one, for example), which seems to bypass the preamplifier and converter (it doesn't, they're built into the microphone).

So which is better? The Samson microphone above costs $80 USD, while the sm57/presonus/m-audio chain costs under $500 USD. People routinely use chains costing thousands of dollars. Again, you get what you pay for, but it's entirely possible to get a good sound out of cheap gear. The "best" could thus be defined as what fits in your budget and you can use to get the sound you want.

A microphone is not used for many signals. For example, a bassist could go direct (by using a Hi-Z in, for example), or a hardware synthesizer could have a digital output, or the synthesizer could be in software. Each example implies, or even dictates, its own signal chain. However, every analog signal must be converted to digital at some point in order to be recorded in the Mac.

A note about mixers: given the state of interfaces today, it is not absolutely necessary to use a mixer, though some like to and it's easy to integrate into a setup. There has been a lot of confusion regarding the relationship between mixers and computer/audio interfaces, which is understandable given some feature overlap.

When it comes down to it, mixers are handy if you want to mix together signals outside of the computer. They can also offer a number of microphone preamplifiers and EQ's on a budget, plus offer some handy monitoring features. However, cheap ones are often considered to have poor quality. The bottom line is they can be useful but aren't always necessary, depending on the setup.

After the Sound Gets In

There are a number of programs which allow multi-track recording, such as GarageBand and Digital Performer. Ideally, the choice of program (or DAW -- Digital Audio Workstation) should be made before the choice of hardware. This is necessary if you end up going with ProTools, because its maker, Digidesign, limits the hardware choices available.

In all situations, though, it will be necessary to hear what's been recorded, such as when doing a mix of the song. Many people mix what's called "in the box", meaning the computer will be doing all the math necessary to take the recorded (or generated live) tracks and make a stereo mix of it.

This mix will be routed through a d/a (digital to analog) converter in order to be heard. perhaps it's the one tied to the headphone output, perhaps it's in your computer/audio interface, perhaps you're sending it out the digital s/pdif line to a dedicated d/a converter - there are a number of options.